Matco brakes & mechanical advantage

[JorgeEC-YUQ]

Hello guys,

I have a Kitfox III with MC-4 master cylinders and double pucks and I've been struggling with poor braking since I install them ...

After purging the system several times, making sure the pucks move without restrictions and the pads are in contact with the rotor, modifying the pedals was the only option left. I thought the geometry was right this time, but it wasn't apparently ...

Was anybody able to get the right pedal geometry and the required mechanical advantage (2'5 to 1 or close)? Did anybody try the Matco intensifier sleeves?

Hope any of you can help!
Cheers,
Jorge

[Av8r_Sed]

Hi Jorge,
You need to move the brake cylinder attach lever arm down close to the pedal pivot point. Your mechanical advantage in the current configuration is less than 1.

Reference the MATCO drawing: http://matcomfg.com/pdf/brake4.pdf?Iit=3575&Ict=21

[JorgeEC-YUQ]

Thanks for your reply Paul.

That would be the ideal position indeed. The problem I see by attaching the lever there is that the actuator from the master cylinder is too long (where the clevis is attached). Won't that make my pedals to move backwards (opposite from the firewall) in a extreme position?

I guess it could be adjusted by cutting and making a new thread but sounds like a mission.

According to the diagrams, some source of fork arrangement could be done , any experience on that? Could you send me a picture of your pedals?

Thanks again and merry Christmas!

Jorge

[Dave S]

Jorge,

While I have a different model Kitfox, the old bankrupt skystar company had sent me the wrong master cylinders with my kit......what I discovered is if a person calls up Matco, they can solve just about any problem with this stuff.....for instance, they have several versions of the MC-4 (which have addittional part # designations) and the variations incude different length piston rods as well as different length bodies - I believe they even have a short version of the master cylinder. Matco is also very knowlegeable about applications such as specific Kitfox
models and what works. If you get stuck, might be worth a call or google-up for Matco - explain what you neeed to solve and see if they have a frugal solution. I found them to be very intelligent and helpful.

Sincerely,

Dave S

[jrevens]

Hi Jorge,

Are your brake lines 1/4" or 3/16" o.d.? It's just a thought, & I know it's not your main problem, but 1/4" plastic lines will give a more "mushy" feel & require more pedal pressure than the smaller 3/16" or 1/8" lines.

[JorgeEC-YUQ]

Hi Jhon,

yes, I believe they are 1/4". It seems to be the common size around my place ...